This invention relates to a system for detecting the degree of knocking of an internal combustion engine, particularly, on an automobile.
Concerning internal combustion engines and particularly automotive gasoline engines, it has been proposed to detect the intensity or degree of knocking of an engine by means of a system having a vibration pickup, such as an accelerometer which provides an electrical signal, mounted on the engine body and band-pass filters through which is passed the output signal of the vibration pickup to take out only a paticular vibration component within a frequency band considered to be attributable to knocking of the engine. The vibration signal passed through the filters is subjected to a certain treatment such as a comparison of amplitude peaks with a reference signal thereby to detect the degree of knocking.
As a disadvantage of this system from a practical viewpoint, this system needs to include a complicated circuitry because of the use of band-pass filters and hence becomes considerably costly.